Make GIS data products more accessible

[jbpaduan]

Builds on issue #75
From the main map, define a box, include what type of mission (e.g., AUV only) and what format you need a file in (e.g., geoTiff, UTM), and employing the prioritization of the selected missions (e.g., production only, not testing or failed), create the file requested.

Alternatively, include a modification date in the compilations list as a proxy for how recent and therefore complete, well-navigated, or clean the map is.

[jbpaduan]

For the record, the alternative approach in the comment above has been completed.
For example, on the page
https://smdb.shore.mbari.org/compilations/mappingauvops2016-northernexpedition-figures_clague_gorda-mauv_northgorda_topo_1m_utm/
I see an image and can mouse-over to see the file name that is of a geoTiff, appropriately, and it uses the stem of the name, ignoring, appropriately, the "slope3225-2350" that follows, and clicking on the image downloads it (awesome!).
Need to note, however, there are a lot of broken thumbnails elsewhere, unfortunately, because I haven't strictly made geoTiff file names match the grid names through time, my bad, in retrospect.
I'd still love to have a way people can make their own data products, as in the initial part of the above comment.